The invention relates to a drilling and boring fixture for the adjustable clamping of board-like furniture parts on the work table of a machine for the drilling and boring of sockets or mounting holes in parts of furniture for the installation of furniture hardware.
Certain furniture hardware, such as hinges, joining devices and the like, must often be fastened in bores or mortises in two different board-like cabinet parts, such as for example a cabinet wall and a door leaf or two cabinet walls meeting at right angles, in which case the problem arises that the bores or mortises in the two furniture parts must be aligned precisely with one another, so that the hardware will fit correctly into the bores when the furniture is assembled later on. In the large series production of furniture, these mounting holes are produced on production lines with multiple tools which are precisely located on the parts to be worked and permit absolutely accurate automatic machining. For the production of furniture models in small series or in single units, such production lines are out of the question on account of the high invested costs, and also because the constant changeovers required in the production of furniture models in small series on such production lines requires too much labor. For such cases, therefore, relatively simple machines have been developed for drilling the mortises and mounting holes; such machines have multiple-spindle drill heads with which the larger socket bore for the hinge cup can be machined into door leaves, simultaneously with two additional lateral mounting holes for mounting screws or pins of modern cup hinges and also two holes for the mounting plates of such hinges. These machines are often provided also with a pressing means whereby the particular piece of hardware can be forced into the mounting hole after the latter has been drilled. In these relatively inexpensive machines, however, all that is established, or that can be quickly and easily adjusted, is the distance of the holes from the adjacent edge of the door leaf or cabinet wall, while the vertical location of the hole has to be measured and marked; this calls for time-consuming measurements, and still it is not possible to avoid errors. Consequently, the holes in two different furniture parts, such as for example the mortises in the door leaf for the hinge cups on the one hand and the mounting holes for the mounting plates of the corresponding hinges, may be out of alignment. Particularly when vertically spaced holes have to be produced on two associated furniture parts of different length for a plurality of hardware parts--for example when a door leaf has to be mounted by two or three hinges on a supporting wall of slightly greater height--there is danger of misalignment of the associated holes on the two furniture parts.
It is therefore the object of the invention to create a drilling and boring fixture which can be installed on the above-described machines for creating mortises and fastening holes, and which will permit a precise alignment of the furniture parts relative to the drill head on the work table of the machine such that the fastening holes which are about to be made in a furniture part will have the proper vertical spacing, and will furthermore be precisely aligned with the fastening holes previously made on the associated second furniture part.